AAT2504
Adjustable 3-Channel Regulator
Pin Descriptions
Pin #
1
2
3
4
Symbol
FBB
ENA
ENB
MODE/SYNC
Function
Feedback input pin for LDOB. This pin is used to regulate the output of LDOB to the desired
value via an external resistor divider.
Enable pin for LDOA. Active high.
Enable pin for LDOB. Active high.
PWM operation and oscillator synchronization pin. Connect to ground for PWM/Light Load
operation and optimized efficiency throughout the load range. Connect high for low noise
PWM operation under all operating conditions. When connected to an external clock, the
internal oscillator is disabled and the step-down converter is synchronized to an external
clock applied to this pin (PWM only).
Feedback input pin for the step-down converter. This pin is used to see the output of the
converter to regulate to the desired value via an external resistor divider.
Ground connection pin.
Main power ground return pin for the step-down converter. Connect to the output and input
capacitor return.
Connect inductor to this pin. Switching node internally connected to the drain of both high-
and low-side MOSFETs.
Input supply voltage for the converter. Must be closely decoupled.
Not connected.
Bias supply. Supply power for the internal circuitry. Connect to input power via low pass filter
with decoupling to AGND.
Enable for the step-down converter. Active high.
Power-OK pin with open drain output. It is pulled low when the OUTA pin is outside the regu-
lation window. Place a pull-up resistor between POK and OUTA.
Feedback input pin for LDOA. This pin is used to regulate the output of LDOA to the desired
value via an external resistor divider.
LDOA output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Input voltage pin for linear regulator A; should be closely decoupled.
Input voltage pin for linear regulator B; should be closely decoupled.
LDOB output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Exposed paddle; connect to ground directly beneath the package.
5
6
7
8, 9
10
11, 12
13
14
15
16
17
18
19
20
EP
FB
AGND
PGND
LX
VP
N/C
VIN
EN
POK
FBA
OUTA
VLDOA
VLDOB
OUTB
2
2504.2007.06.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
